Colleges and universities have widely responded to the expectation that they should work toward, operate under, and live by principles of sustainability. Eighty-nine of the 260-plus institutions of higher learning in New England (34 percent) have signed the "American College & University Presidents Climate Commitment" to guide their institutions and their programs toward climate neutrality. Public institutions have been significant leaders, with more than half of New England's public colleges and universities (57 percent) participating. Interest in sustainable development comes from many sources, but first and foremost, from the interest of students, faculty, administration and the wider community in moderating or reversing climate change. While interest in sustainable development is strong, justifying expenditures for sustainable development in a difficult economic environment can be challenging. Nevertheless, the author notes, strong economic and community-relations rationale argues for reducing carbon footprint, using permeable pavement and other high-tech surfaces to drain rainwater, cutting energy use and otherwise pursuing sustainable goals.